Manganese-based single-molecule magnets (SMMs) are molecules with a large ground-state spin, S, and a magnetoanisotropy of the Ising-type (negative zfs parameter, D). As a result, they display the classical diagnostic property of a magnet, hysteresis loops in magnetization vs applied magnetic field scans. SMMs represent a molecular approach to nanoscale magnetic materials and also display interesting quantum properties, such as quantum tunneling of magnetization and quantum phase interference. In recent years, we have been linking two or more SMMs together in order to introduce weak exchange interactions between them: this is important for potential applications, such as for qubits in quantum computing. In the present work, we have obtained two new supramolecular clusters, [Mn3]2 and [Mn3]8, with very interesting structures formed by using two new bis-oxime linkers, 1,3-phenylenebis(pyridin-2-ylmethanone)dioxime (1,3-ppmdH2) and 1,4-phenylenebis (pyridine-2-ylmethanone)dioxime (1,4-ppmdH2), respectively. The synthesis, supramolecular structures, and magnetic characterization of these SMM aggregates will be described.